This invention relates generally to fuel injectors in engines, and more particularly to a method for installing fuel injectors with at least two electrical actuators in the engine.
In some diesel engines today, there are a plurality of fuel injectors, each having only one electrical actuator. The electrical actuator can be coupled to an electronic controller, in part, by attaching one connector containing electrical leads to each fuel injector. For instance, a one-electrical actuator fuel injector such as that shown in U.S. Pat. No. 5,616,037 issued to Lorraine et al., on Apr. 1, 1997, requires only one electrical connection for each fuel injector.
While the method of utilizing one wiring connector for each electrical actuator has performed well in fuel injectors with one electrical actuator, the method may need improvement for fuel injectors with more than one electrical actuator. It is becoming more common to install in diesel engines fuel injectors having multiple electrical actuators. For instance, in several diesel engines, there are a plurality of fuel injectors having two electrical actuators located at two different positions within the fuel injector. Each electrical actuator includes a solenoid or other device, i.e., piezo that, at least partially, controls a valve within the fuel injector. A first electrical actuator is positioned in an upper portion of the fuel injector and, ultimately, controls the movement of a plunger in the fuel injector. When the plunger advances, fuel within the fuel injector can be compressed. A second electrical actuator is positioned in a lower portion of the fuel injector and controls, in part, the timing of injection events. A wiring harness is in electrical communication with an electronic controller. If each electrical actuator must be electrically connected to the wiring harness via its own electrical connector and electrical leads, there will be two wiring connectors that must be attached at two different locations on the fuel injector.
If a connector is attached to the electrical actuator in the upper portion of the fuel injector and a different connector is attached to the electrical actuator in the lower portion of the fuel injector, there exists a possibility that the two connectors will be interchanged. Thus, the upper electrical actuator would be connected to the electrical leads for the lower electrical actuator, and vice versa, causing the fuel injector to malfunction. Further, because the two electrical connections are located at different positions within the fuel injector, the process of attaching the connectors is labor intensive and is not suitable for automated assembly. The lower connector is difficult to connect when the injector is assembled to the engine head with a valve train. Thus, the manufacturing costs for connecting both actuators to the wiring harness is high. Lastly, the prior art, whether it includes a fuel injector having one or two electrical actuators, often utilizes a clip to attach the connectors to their respective electrical actuators. However, over time, the engine vibrations loosen the electrical connection between the connectors and the electrical actuators, causing the fuel injector to malfunction.
The present invention is directed to overcoming one or more of the problems as set forth above.
In one aspect of the present invention, a fuel injector includes a fuel injector body in which a first electrical actuator and a second electrical actuator are at least partially positioned. Outside an outer surface of the fuel injector body, a first pair of electrical conductors and a second pair of electrical conductors are exposed in a predetermined pattern relative to one another. The first electrical actuator and the first pair of electrical conductors are electrically connected to a first electrical circuit. The second electrical actuator and the second pair of electrical conductors are electrically connected to a second electrical circuit.
In another aspect of the present invention, an engine includes an engine housing to which at least one fuel injector is attached. The fuel injector includes a fuel injector body in which a first electrical actuator and a second electrical actuator are at least partially positioned. A first pair of electrical conductors and a second pair of electrical conductors are exposed outside an outer surface of the fuel injector body. The first electrical actuator and the first pair of electrical conductors are electrically connected to a first electrical circuit. The second electrical actuator and the second pair of electrical conductors are electrically connected to a second electrical circuit. A connector of a wiring harness is attached to the fuel injector. The connector includes a first pair of electrical conductors and a second pair of electrical conductors that are electrically connected to the first pair of electrical conductors and the second pair of electrical conductors of the fuel injector, respectively.
In yet another aspect of the present invention, there is a method for installing a fuel injector in an engine. The fuel injector is attached to an engine housing. There are two pairs of electrical conductors exposed outside an outer surface of a fuel injector body. A connector of a wiring harness is attached to the fuel injector, at least, in part, by connecting a first pair of electrical conductors and a second pair of electrical conductors of the wiring harness to a first pair of electrical conductors and a second pair of electrical conductors of the fuel injector, respectively.